Chord Harmonization over major scales

by: T.Franca

Introduction

Chord harmonization over a scale is a fundamental tool to understand the correct use of harmony in a theme. It is a concept that many hobbyists do not know, but they are doing it unconsciously when they are "searching" for a chord that "sounds good" over a certain progression. So we can say that "harmonizing" a scale of chords is the process of identifying what are the chords that "sound good" over a particular scale.

The reverse is also true: if we search for a scale that fits well in a given chord progression, what we are doing is finding the underlying scale of that chord progression, which can be helpful to understand what we are doing.

What is it used for?

1. The harmonization of chords is important for anyone who wants to compose: After an initial idea of a riff or a progression for a song, chord harmonization helps us to identify more easily chords that fit on the same scale, without having to "guess".

2. The harmonization also allows us to identify the underlying progression scale: this helps us determine what are the important degrees of a chord progression.

3. Because a chord progression has an implicit musical scale, determining it helps us on expanding or harmony and to create solos or “riff’s” over the progression. Chord harmonization explains how to find this scale.

What is it?

It's simple: You use each note of the scale as the underlying basis for the chords and then ensure that all the notes of that chord belong to that scale.

What we want is to identify a chord corresponding to each note of the scale, ensuring that all the notes of that chord still belong to the scale. Let's start with the chord of C:

1st Note

1st interval

2nd interval

C

C + m3 = D # (off the scale!)
C + 3 = E (standing on the scale)

E + m3 = G(standing on scale)
E + 3 = G # (off the scale!)

The 1st interval is a major 3rd, so this is a major chord

The 2nd interval is a minor 3rd, so the chord is not augmented: it is a normal major chord.

Thus, in the scale of C major, the harmonized chord of key C is C + E + G (C major – what a surprise huh ?).

We’ll post some quick references on chord formation soon.

Let’s try to harmonize the D chord in the C major scale:

1st Note

1st Interval

2nd Interval

D

D + m3 = F (standing on the scale)
D = 3 + F # (off the scale!)

F + m3 = G # (off the scale!)
F = 3 + A (standing on scale)

The 1st interval is a minor 3rd, so this is a minor chord

The 2nd interval is a major 3rd, so the chord is not diminished: it is a normal minor chord.

We concluded that the in C major scale, the harmonized chord of D is D + F + A (D minor). We can continue like this for all the notes of the C major scale from to get all harmonized chords. Let’s just harmonize the B chord, because it is the only case is this example where the result is a diminished chord:

1st Note

1st Interval

2nd Interval

B

B + m3 = D(standing on scale)
B + 3 = D # (off the scale!)

D + m3 = F (standing on the scale)
D = 3 + F # (off the scale!)

The 1st interval is a minor 3rd, so this is a minor chord

The 2nd interval makes places the last note of the chord on the diminished 5th note of the scale, so the chord is diminished.

Thus, In the C major scale, the B chord is diminished! (Bdim or Bº = B + D + F).

Simple rule:

If we did this exercise to all the notes of the C major scale, we would come to the conclusion that the harmonized C chord scale is:

This is true for all the major scales! Harmonized chords are always in this sequence: Major, minor, minor, major, major, minor, diminished. For example, the harmonized chords in the major scale of G are:

Notes:

For a specific scale there are a number of chords that have all the notes over that scale (7th chords, suspended chords, etc).

Conclusion:

The harmonization of a range of chords gives us a guarantee for consistency of a harmonic chord progression over an underlying scale.

Analyze the chords of a song you like, probably most of the theme works a harmonized chord scale! Sometimes, to give "momentum" to the theme, the composer leaves the harmonized scale in bridges or bridges, or maybe changes the key of the song, but then comes back to the same scale. There are some very common cases that work well, such as the 4th chord in the scale changing to a minor chord, which exits the harmonized scale to denote a change in key.

It is also possible to harmonize a minor scale, but in this case there are three possible scales, Natural, Harmonic and Melodic. Harmonization rules are exactly the same as for the major scale. See our page on Chord Harmonization in minor scales (coming soon).

Chord harmonization also applies to 7th chords, just ensure that the 7th is also the underlying scale. See: Harmonization of 7th chords (coming soon).